5HA99Y,
I have 2 suggestions for you.
1. Alpha Shepherd wrote "Be Dumb" under the name Jekket. The body of that file can be looped effectively. The entire file with induction, deepener, body and wakeup is excellent and really the only one that I am aware of that is specific to becoming "dumb". It does not require the subject to stroke, join a gym, or even workout. You might check out his other files on WMM and on Patreon (
https://www.patreon.com/AlphaShep. (I think you'll like his style) I don't know if he has re-released "Be Dumb" on Patreon.
2. Majorpixel has a couple of "dumb" files.
https://www.warpmymind.com/index.php?ga ... link=14086 This one is more dumb than jock but it may not fit your requirements. I have used Majorpixel's files in the gym while doing cardio because they are all exactly 20 minutes long, uniform, and loop without distraction.
Hope one of these will help you.